Late last week, GOP Sen. Rob Portman shocked commentators and fellow politicians by reversing his position on same-sex marriage, saying that his decision was inspired by his son, who is gay. In my latest for “Figuring Faith,” I show that this “family and friends effect” is quite potent when it comes to the issue of same-sex marriage:

Even on controversial issues such as same-sex marriage, public opinion research demonstrates that relationships with family and friends often trump political and religious affiliations.

Since 2011, polls have consistently shown pluralities or slim majorities of Americans—including many religious Americans such as Sen. Portman’s fellow mainline Protestants—have come to support allowing gay and lesbian people to marry legally. It is also well known that the polls also show as much as a forty-point generation gap between the youngest and oldest American adults on this issue.